Process for the hydrogenation of hydrocarbons



Aug. 25, 1959 w. HERBERT ET Al- 2,9015423 PROCESS FOR THE HYDROGENATIONOF HYDROCARBONS Filed Nov. 23, 1955 /mRL-HE'WZ ESHHR, HANS-WENT@ GIQSSATrOAM/eyg 2,901,423 Patented Aug. 25, 1959 United States APatent @thatPROCESS Fon THE HYDRoGENATloN oF HYDRocAnBoNs Wilhelm Herbert, Frankfurtam Main, Carl Bratzler and Oskar Dorschner, Bad Homburg vor der Hohe,and Karl-Heinz Eisenlohr and Hans-Werner Gross, Frankfurt am Main,Germany, assignors to Metallgesellschaft Aktiengesellschaft, Frankfurtam Main, Germany Application November 23, 1955, Serial No. '549,581

Claims priority, application Germany November 25, 1954 (Filed under Rule47(a) and 35 U.S.C. *116) 7 Claims. (Cl. 208-264) The present inventionrefers to a process of catalytic hydrogenation of hydrocarbons orhydrocarbon fractions in the presence of hydrogen, in using sulfurresistant catalysts. Sluch hydrocarbons or hydrocarbons fractions aree.g. obtained from coking, low temperature distillation, or thegasification of coal, lignite, oil shale or other solid fuels, or elsein the reiining of liquid fuels such as mineral oil, tar, tar oil, orthe like. The herein 4described process is eg. suited for treating suchhydrocarbons as benzol, gasoline, gas oil, middle oils, or fractions ofthe lsame and other hydrocarbons, preferably such which are boilingwithin a range of up to 360 or also 400 C. By means of catalytichydrogenation, organic sulfur, nitrolgen and oxygen compounds, resinformers and similar impurities are eliminated from the hydrocarbons. Itis the object of the invention to use for such catalytic `hy-Idrogenation hydrogen-containing gases such as town gas, i

'coke oven gas, 10W temperature distillation gas, Water jgas, gasesobtained from refining or reforming mineral loils and other liquidfuels, synthesis final or recycled gas, or similar gases containing asessential compounds, besides hydrogen, carbon oxide, methane, or otherlowboiling, particularly gaseous hydrocarbons, and, in some cases,carbon dioxide, nitrogen, water vapor, or two `or `several of thesesubstances, and to effect the catalytic vhydrogenation in such a way asto eliminate or at least 'vastly reduce the hitherto unavoidableformation of "deposits and incrustations in the used vaporizers, heatexchangers, heaters, lines, and other equipments, as well :as on thecatalysts.

Moreover, the present invention aims at operating the 'process in such away as to 'impart to the used catalysts :a long service life of manymonths. A further object of the invention is to impart to the gases usedfor catalytic hydrogenatiom by means of a treatment effected prior tozrefining, such properties which will make those gases :speciallysuitable for refining. vA further object of the jpresent 'invention isto produce in the process proper, by conversion of carbon oxidecontained `in the hydrogencontaining gas, part of the hydrogen requiredfor catalytic refining, using for the conversion appropriately the samecatalyst used for catalytic refining, and carrying out the conversionand catalytic refining simultaneously.

In accordance with the present invention, town gas,

coke oven gas, low temperature distillation gas, water `;gas, gasesobtained from refining or reforming mineral itween 50 and 420 C.,appropriately 20G-400 C., before being brought into contact with thehydrocarbons to be refined. Only after such pre-treatment, therespective gas Yis introduced, into the refining process proper. For ex-'amp1e, .the gas, after -suoh pre-treatment, is passed through thehydrocarbons to be refined, while the same are completely or partlyvaporized, it being at the same time possible to add some gas which wasrecycled through catalytic refining. The mixture of hydrocarbons to berefined and hydrogen containing gas will then iiow through the heatexchangers and heaters into the reactor and from there into the devicesprovided for separating the refined hydrocarbons from the gas, whichlatter may then be used for refining-appropriately in branching olf apartial iiow from the process.

By preparing the hydrogen containing gas in accordance with the presentinvention, it is possible to effectively prevent a disturbance ofhydrogenating refining by the formation of deposits in the vaporizersand heat exchangers or on the catalyst itself and in the connectinglines. The gas treated according to the present invention may beintroduced into the hydrogenating treatment of the hydrocarbons atvarious points. t For example, it is possible not only to pass the gasseparately or mixed with recycled gas through the vaporizer for thehydrocarbons, but also to add it only before the reactor is entered.

Working temperatures are normally about between 50 C. and the reactiontemperature of the subsequent catalytic refining, e.g. the process isoperated at temperatures between and 240 C. Appropriately, thetemperature of the catalyzer is chosen in such a way that a conversionof carbon oxide into methane will not take place when rcarbon oxidecontaining gases are treated. The treatment of the fresh gas accordingto the present invention is effected with the modification that thetreated gas, `when passed through a sulfuric acid formaldehyde solution(30 parts by Volume 66 sulfuric acid on l part by volume 40%formaldehyde) for a period of several minutes will produce only a weakbrown coloring. The working temperature, treating period, and quantityof catalyzer may easily be fixed by tests.

In this connection, it will not be necessary to Work under pressure. Theprocess will pass oi satisfactorily also at normal pressure or, ifnecessary, at reduced pressure. Thus, it is possible in accordance withthe present invention to treat the gas also prior to compression, and tocompress it subsequently to the pressure used for catalytic refining,which is usually above atmospheric pressure, e.g. at 20-100 at.

The process according to the present invention olers the furtheradvantage that the catalyzer can be operated with rather varying degreesof efficiency. The load may be `reduced down to` 10 N m gas per 1 :n.3catalyzer and l hour. On the other hand, it may lalso be maintainedsubstantially higher, e.g. at up to 1000 N m gas and above per mcatalyzer an hour.

The catalyzer is eg. applied in extended cylindrical chambers into whichthe necessary heat may e.g. be introduced from outside. It is forexample profitable to Voperate the process in such Aa Way as to heat thecatalyZer, and to introduce the gas into the same at a temperature lowerthan reaction temperature, so that the gas is brought to reactiontemperature when passing the catalyzer. In this case, the necessary heatsupply to the catalyzer may be effected by heat exchange between theentry gas and the exit gas, if necessary, with additional heat input, itbeing possible to use for the heating that heat which is produced by thesubsequent catalytic refining. Other methods of heating may also beadopted, e.g. a pre-heating and thus 'a heating of the gas may beeffected by feeding oxygen into the fresh gas at the catalyzer. Toachieve this, the process may also -be operated with a catalyzer in theform of 'a fluidized bed or suspension. lt is also possible to add thefresh gas to the hydrocarbon vapors emanating from the `vaporizer or, asthe oase may be, to their mixture with recycled gas, and to pass thethus obtained mixture through the catalyzer, which effects the treatmentof the fresh gas in accordance with the present invention, provided thatthe temperature of the mixture should be kept sufficiently below thetemperature of the hydrogenating refining, eg. at abt. 180-200 C. Inthis case, the catalyzer is indirectly heated by means of the gasleaving the reactor of the hydrogenating refining, whereby the gas vapormixture fiowing into the reactor is simultaneously heated. There isanother method of utilizing the heat produced by catalytic refining forthe process according to the present invention, eg. in such a way as topass the fresh gas separately or mixed with recycled gas through aeatalyzer working by heat exchange with vapors emanating from thereactor of the catalytic rening, conducting such gas from the catalyzerinto the vaporizer for the hydrocarbons.

The process according to the present invention is e.g. operated in sucha way `as to compressing the hydrogenous gas required for the refininghydrogenation to working pressure and to pass the gas over the contactmasses, profitably without cooling after compression, i.e. at elevatedtemperature, appropriately after a second heating.

As catalyzers for preparing the fresh gas for hydrogenating refining inaccordance with the present invention, it is possible eg. to use metaloxides and/or sulfides of the metals of the 6th land 8th groups of theperiodic system. Well suitable are in particular the knownYhydrogenating catalysts which contain as base materials tungsten,molybdenum, vanadium, cobalt, chrome, nickel, or iron, and which mayfurthermore contain zinc, magnesiurn, or similar oxide compounds and bedeposited on such carrier substances as activated carbon, silicagel, oralumina. These catalyzers may also contain two or several of the saidmetals.

It has proved specially profitable to use those sulphur resistantcatalyzers which are applied for the cracking or hydrogenating rening ofhydrocarbons under pressure. But `also with alkalized iron catalyzerssuch as have hitherto been used for the catalytic conversion of organicsulfur compounds in synthesis gases, useful results could be achieved.

For example, molybdic acid on alumina is used as catalyzer, molybdicVacid concentrations of abt. 10% being applied. Another highly activecatalyzer for the treatment of the fresh gas according to the presentinvention can eg. be obtained in such a manner as to intimately mix 70parts by weight of a commercial aluminum oxide hydrate with bayeritestructure, which essentially in the catalyzer serves as a carrier, with18 parts by weight molybdic acid, 8 parts by weight cobalt hydroxide,and 4 parts by weight graphite. This mixture is pressed into the form ofsmall cylinders. The catalyzers may be introduced into the process inthe form of their oxides. Under the action of the present hydrogensulfide and of the hydrogen sulfide formed by the cracking of organicysulfur compounds respectively, as `well as of hydrogen, the metaloxides will in the course of the process gradually change over into apartly sulfiidic and partly metallic form. However, the catalysts canwithout difficulty be sulfurized or reduced in the known manner beforebeing applied and used in the process in their suldic and/or metallicform.

Also precipitating catalyzers have proved to be useful, produced e.g.`in such a way' that aluminum salts and one of the salts of the saidmetals or mixtures of such metal salts are precipitated jointly, e.g. inthe presence of a carrier, or that alumina or another carrier substanceis impregnated with one or several of such metal salts, converting thesalts into their oxide form, eg. by heating.

Also the catalyzer used up in hydrogenating refining may advantageouslybe used for the process according Ato the present invention. whichprocess offers in this case the additional advantage of using aspecially lowpriced catalyst.

It is possible to use for the process according to the present inventionstarting gases kwith different hydrogen and carbon oxide contents. Ahydrogen partial pressure of under 25 at. and a hydrogen and carbonoxide partial pressure of up to 40 at. have proved specially profitable,the carbon oxide partial pressure being appropriately between 0.1 and 15at.

It is profitable to use as hydrogen containing gas those gases whichemanate from the chambers of coke ovens of conventional structuretowards the end of the carbonizing period. Such gases may still beimproved by passing methane or methane-containing gases, town gas, ornatural gas, through the glowing coke during the last part of thecarbonizing period.

A saving of hydrogen required for hydrogenation can be realized bypassing water vapor through the catalyzer being used for the catalyticrefining of the hydrocarbons. Surprisingly, the presence of water vaporwill not interfere with, but frequently favor the refining. Neither willany damages to the contact occur, the sulphur resistant contact beingnormally used for refining. The present invention offers the greatadvantage that depositions of carbon onV the contact are eliminated,even if the refining takes place at relatively high temperatures of e.g.over 400 to up to 500 C. Moreover, lit is possible to avoid a reductionof the octane number in hydrogenating refining. In some cases, even animprovement of the octane number is obtained. The quantities of watervapor required in accordance with the present invention amount Vto about5-5 0% by volume, calculated on the gas freshly entering the process.About ILS-35% by volume are profitably used. When working with recycledgas, somewhat'larger quantities of water vapor, calculated on the freshgas, are recommendable.

The water vapor may be introduced into the process at various points. ltmay be added to the gas fiowing into the reactor in which the catalyticrefining of the hydrocarbons takes place. It is also possible tointroduce the water vapor into the reactor separately from the gas. Itwill be appropriate in many .cases to admix the water vapor already tothe hydrogenous gas freshly entering theprocess, so that the water vaporwill pass together with the gas the pre-treatment of the gas. Also inthis case, the presence of water vapor will be advantageous; inparticular, the water vapor will protect the catalyzer of thepre-treatment against a premature depletion, which may occur in thecourse of time e.g. by deposits of carbonblack or incrustations on thecatalyzer. Moreover, the addition of water vapor in the pre-contactingwill Amake the gas better suited for the subsequent catalytic refining.In addition, the conversion of part of the water vapor will effect acertain increase of the hydrogen content of the gas. After thepre-contacting of the gas freshly entering the process, a cooling of thegas which might result in a separation of water vapor will, of course,be avoided. In the case of a two or multiple stage precontacting of thegas freshly entering the process, the water vapor may be added eitherbefore the first stage or only before one of the subsequent stages.

For example, it is possible to use for the process an apparatus asdiagrammatically set up and exemplified in thedrawing.

The hydrocarbon fraction to be refined, eg. benzole, fiows from thecollector tank i through the Vline 2 to vthe pump '3, 'from which it ispumped through the line 4,

the `pre-heater 5, and the line 6 to the'benzole vaporizer 7, whichlatter is maintained at the desired vaporizing and 11. A1v thistemperature, the vapors flow through the pipe 13 into the reactor'*i4-used for the hydrogenating refining, in` which the vcatalyst V15 iskarranged kon a from the vaporizer 7 through the line 23 and the cooler24 to the line 25, through whichit may be conducted e.g. to a tardistillation or other distillation plants, in which the higherlhoilingsubstances of the said portion may be returned, if desired, to therefining, e.g. benzole` refining.

The hydrogen containing gas requiredrfor the catalytic refining may beadmixed to the benzole or the like flowing through the line 4 by passagefrom `the line 26, e.g. through line 27. This gas in mixture with thebenzole into the vaporizer through the heat exchanger 5. It may also beled-mixed with the recycled gas, if deaired-through the line 28immediately into the vaporizer 7. The gas which is recycled flows fromthe separator 21 through the pre-heater 29 and the line 30 into thevaporizer. A portion of the recycled gas is branched off from theprocess at 31 in order to maintain the composition of the recycled gasconstant.

If thehydrogen containing gas would be introduced into the catalyticrefining immediately through the line 26, coke-like deposits would formon the heat exchangers and ll at the temperature of about l80-240 C. Asa result thereof, the difference pressure in the plant caused by theflow resistance, which is 0.5 at. when starting the run, will rise to2.5 at. and higher within a few days. After about a week of each run,the heat exchangers consisting of nests of boiler tubes lying within thesaid range of temperature will be clogged with coke-like deposits, sothat the plant will have to be shut down. Also in the vaporizer such` asconstructed and operated eg. in accordance with the German Patents930,224 and 930,225, deposits will be found which reduce the passage ofthe charge to be vaporized and interfere with the vaporization.

In accordance with the present invention, the fresh gas is compressedand first of all passed through a pre-heater 32, from which it flowsthrough the line 33 into the pressure-resistant container 34, which isheatable in a known manner. For 100 111.3 fresh gas per hour, about 100l. catalyst are employed in 34 at a pressure of e.g. 35 at. The freshgas is heated by means of indirect heating to that temperature which isthe optimum for this catalyst. The catalyst consisting of a mixture ofmolybdic acid, cobalt hydroxide, alumina, and graphite is operated,according to the composition of the fresh gas, within a temperaturerange of about 100-400 C., appropriately 180- 350 C., e.g. at about200"l C.

The gas leaving the catalyst has eg. the following composition:

CO2-i-H2S vol. percent-- 2.0 CnHm do 0.5 O2 d0 0 CO do 12.4 H2 do 55.8CH., do 24.7 N2 dO 4.6

The gas contains abt. 0.1 g. hydrogen sulfide per ncrmal cubic meter,but is free from all other substances wh-ich might react with the resinformers contained in the hydrocarbons to be refined. While the untreatedcoke oven gas causes a :black coloration in a formaldehyde/ sulfuricacid solution in a few seconds, the `gas treated in accordance with thepresent invention will `only color such a solution light brown afterbeing passed therethrough for several minutes.

rPhe gas treated in accordance with the present invention is thenadmixed, appropriately without cooling, to the recycled gas prior to itsentrance into the vaporizer, or introduced already into the hydrocarbonsto be vaporized in front of the preheater 5.

After removing the injurious components of the fresh gas in accordancewith the present invention, both the separation of elemental sulfur andthe formation of resin and coke deposits in the vaporizer and heatersystems are suppressed.

Even when the refining is effected in the liquid phase, or when amixture of liquid and vaporous hydrocarbons is refined, all theinjurious deposits and incrustations are eliminated by the process ofthe invention.

The reactor to be used may `advantageously consist of a constructionbeing essentially composed of a pressure bearing outer jacket and aninner jacket in which the catalyst is arranged in such a Way as to reston a perforated bottom. The interior jacket is designed for protectingthe pressure bearing jacket in order Ito withhold overheatingyteniperatures from the pressure bearing jacket and to ensure thatoccurring corrosions, it any, Will only arise in `the interior jacket.The space between the pressure bearing jacket and the interior space isconnected with the gas chamber of the reactor, so that the interiorjacket is essentially not subjected to pressure and may be designed witha very thin Iwall thickness. The reactor is closed at the top by a lid.On this lid, a `gas heater is arranged which is filled with metallicbodies such as Raschig rings, iron balls or 4the like. Around the saidheater, an inductive heating is arranged, which is switched on, ifnecessary, and will then effect a heating. The gas vapor mixtureentering into reaction is introduced through a connection piece into thecontact `oven and is heated to reaction temperature at the fillingbodies by the action of the induction and eddy currents. It will thenflow through the contact layer, in which the decomposition of 'thesulfur, nitrogen and oxygen compounds takes place. The temperature ofthe `gas is thereby increased by abt. l050 C., and the gas leaves thecatalyst chamber in a purified condition. The reactor is surrounded witha heat insulating coat. When operating the process according to thepresent invention with addition of water vapor, the latter may alreadybe added to the hydrogenous gas freshly entering the process, and willthen be entrained by the said gas through the catalytic pre-contactingfor hydrocarbon refining. In the pre-contacting and refining stages, thewater vapor effects a substantial reduction of the hydrogen consumption.Moreover, it results in an advantageous equalization of temperature inthe catalyzer, which specially accurs during the hydro genatingcatalytic refining of the hydrocarbons.

Example When gasifying a slightly caking long flame igas coal by meansof oxygen and water vapor at a pressure of 20 at. for producing longdistance gas, tar, tar oil, and gasoline are obtained as byproducts. Thesubstances are obtained in a known manner from `the gas produced by .thegasification and subjected to pressure, which is in the case of gasolineachieved eg. :by treating the gas with Wash oil. Tar and tar oil arejointly subjected to a distillation, during `which a fraction extendingfrom the boiling point to a temperature of abt. 2l0 C. is inter aliatake off separately. This light oil fraction containing abt. 25% byvolume of phenols may be dephenolized in a known manner, e.g. byextraction with hot dephenolized water or with lalkali solution.However, such depheno-lization is not absolutely necessary, as thephenols, even if they are contained in the starting material in largerquanti-ties, are converted into hydrocarbons during the hydrogenatingrefining. The `gasoline and the equally dephenolized light oil fractionare combined and.` subjected lto catalytic refining for the purpose ofpro ducing a satisfactory motor fuel. e.g. the following composition:

The mixture shows The refining of the crude gasoline is leffected at apressurewhich should advantageously be somewhat above the pressure ofthe long distance gas. So eig. the pressure of the refining plant ismaintained at 25 at. in the case of a long distance gas pressure of 20vat. Through the line, 1,000 normal cubic meters fresh gas per hour areconducted to the compressor, which fresh gas is heated up to atemperature of, 170-180" C. in the heat ex,- changer, which issupplemented by an additional heating equipment, if necessary. To thisgas, 250 kilos` per hour of water vapor being-available at a pressure of36 at. are added through the line 5. The hydrogen containing gas enterstheV Vaporizer together with the water vapor, which vaporizer ismaintained at a Itemperature of 190-220 C. by meansv of the heatersystem. 1,000 kilos crude Agasoline per hour are introduced into 4thevaporizer through the line. From the line, l5 kilos vaporizing residuesper hour are drawn off, which may be transferred back into the tarorb-tained in gas production, e.g. prior to the distillation of theformer. 1,000 normal cubic meters gas, 250 kilos water vapor and 985kilos gasoline vapor per hour, which are jointly heated up to atemperature nearly reaching reaction tempera-- ture by means of therheat exchangers as well as the heater, are leaving the vaporizer throughthe line.

The refining loss amounts to 39 kilos per 1,000 kilos crude gasoline.The refined product shows the following composition:

Density at 20 C 0.795 Sulfur percent by weight 0.034 Acid oils percentby volume Initial boiling point C 61 by volume C 74 Final boiling pointC 203 Boiling loss percent 3.2

As the refined product still contains hydrogen sulfide as well asammonia, it is washed with caustic solution and water and then dried. Inmost cases, a further treatment of the refined product may be omitted.In the case of difiicult hydrocarbons, particularly gasolines, it maysometimes occur that the refined product is not absolutely stable tolight. However, it is possible without diliiculty to achieve the desiredabsolute stability to light by means of a slight after-treatment eg. bywashing with diluted sulfuric acid and/or treating with bleaching earth,aiu- Inina, silica, gel, activated carbon, or simiar substances in theliquid phase at normal or elevated ltemperatures or in the gas phase, ifnecessary, under pressure. Such treatment, which may be effectedsubsequently torefining by means of the sulfur resistant catalyst, mayappropriately be effected in the presence of the hydrogen containing gasand/ or the water vapor.

Instead of the said after-treatment, a fractioning of the refinedhydrocarbons or hydrocarbon fractions may take place. For it was foundthat when such fractioning is carried out a distillate stable to lightpasses: over head, whilst those substances which cause the decelerationremain in the distillation residue. The latter may be kept comparativelysmall, e.g. only at abt. 1-l5% of the fractionation` feed. It will beappropriate to recycle the distillation residue to the hydrocarbons orhydrocarbon fractions to. be refined. In specially difficult cases, suchfractioning as well as the after-,treatment may be appliedby means` ofdiluted sulfuric acid, bleaching earth, orthe likeone after the other,in any desired sequence,

The heightr of the catalyst bed may be measured at about between 3 and15m. propriate to divide the catalyst bed into two or several: layers,as the mechanical resistance of the catalyst is sometimes insufficient,if the same is. arranged in one-single highv layer. Moreover, it isadvantageous to work with comparatively high flow velocities of eg. 2 or3^ m. per second. The main effect of such fiow velocity consists in;that the catalyst is uniformly tiown through and heated; so as to avoidoverheating in places, even if the catalyst cross section isV measuredcomparatively large, eg. if theI catalyst is without any cross sectiondivision arranged in. a shaft furnace. Also a horizontal division of thecatalyst bed into two or several layers will alleviate the danger ofover-heating.

It is possible to introduce some of the vapors or gases` being in theprocess according to the present invention, e.g. recycled gas or freshgas or hydrogen containing gases, between two layers at one or severalplaces of thev catalyst bed. The temperature of the introduced gasesand/or vapors may be above or below the reaction. tem-.A perature atwhich the treated gas/ vapor mixture enters the space between twolayers. In the first case, thein-A troduced gases or vapors are thusused for introducing heat into the reaction, whilst in the second casethey will reduce the reaction `temperature at whichv the treatedigas/vapor mixture enters the next layer. Besides this temperaturecontrol, it is possible to achieve, e.g. by introducing fresh gasbetween the catalyst layers, an improvement of the reaction byincreasing the hydrogen and/ or carbon dioxide concentration. Similareffects may be obtained by introducing water vapor between the layers.at one or several places of the catalyst bed resulting in. a conversionof Water vapor and carbon dioxide into hydrogen.

As already observed, the reaction temperatures may fiuctuate withincomparatively wide a range; they normally are between abt. 300 and 500C. Such reaction temperatures may be adjusted by heat exchange with thegas/ vapor mixture flowing from the reaction and, if nec-` essary, byadditional heating. ln case that the gas/vapor mixture leaves thecatalyst with comparatively high temperatures and Vthat a comparativelyhigh temperature rise of eg. C. takes place in the catalyst bed, it ispossibleI also with a heat exchange between the gas/vapor mixtureentering the reactor and liowing from the reactor, to easily adjust thedesired temperature in such a way that only part of the gas fio-wingfrom the reactor is passed through the heat exchange, the heat of theother part being used for other purposes inside or outside the process.

The number of layers into which ythe catalyst bed is divided inaccordance with the present invention may fluctuate within lthe limitsof abt. 2-20. This number is in each separate case chosen with themodification that the mechanical properties of Ithe catalyst should notbe overstressed, and that suitable reaction conditions, especiallytemperature and iiovv` conditions, should be provided. It is alsopossible to consider the gas quantities to be used in each case, e.g. insuch a way as to choose a greater number of catalyst layers when. largerquantities of gas are cycled.

When introducing cold gas between the layers, it will be appropriate tointroduce more gas for smaller amounts of cycled gas and less gas forhigher amounts of cycled gas.

For example, it will be appropriate, for increasing the gas velocity, towork with quantities of abt. 50G-2,000 normal cubic meters of gas perton of starting. material put through.

If large amounts of heat are freed during the reaction, it may beappropriate to cool the catalyst. For example, the catalyst may bearranged in vertical tubes which are sprinkled from the outside by aboilingvcooliugagent.

In most cases, it will: beapf,

The vapors of the cooling agent arising thereby are Withdrawn from thecooling agent chamber and condensed by utilizing the heat involved,whereupon the condensate can be retransferred into the cooling agentchamber. When arranging the catalyst in the said tubes or in a closedcolumn, this arrangement may also be utilized for keeping the catalystat constant temperature. In this case, the tubes of the catalyst chambersubdivided in the horizontal plane are surrounded with a high-boilingliquid, eg. diphenyl oxide. This phase will then effect a heatequalization between the different parts of the catalyst, if such partswill adopt unequal temperatures due to dilerent rates of reaction. t

We claim:

1. In the process for the catalytic hydrogenating retining ofhydrocarbons in which a hydrocarbon ranging from a normally liquid tosolid hydrocarbon is contacted with a hydrogen-containing hydrogenationgas in the presence of a sulfur-resistant hydrogenation catalyst underconditions of elevated temperature and pressure, the improvement whichcomprises effecting said contacting in the additional presence of -50%by volume of Water vapor based on the hydrogenation gas.

2. Improvement according to claim 1 in Which said contacting is effectedin the presence of about -35% by Volume of Water vapor based on saidhydrogenation gas.

3. Improvement according to claim 1 in which said hydrogenation gas is ahydrogen containing gas selected from the group consisting ofilluminating gas, coke oven gas, low temperature distillation gas, andsimilar hydrogen-containing gases.

4. Improvement according to claim 1 in which said contacting is effectedat a temperature of between 300 and 400 C.

5. Improvement according to claim 1 in which said contacting is eiectedby passing said hydrocarbon and said hydrogenation gas through a bed ofsaid catalyst and which includes re-cycling the hydrogenation gas aftersaid contacting and introducing fresh hydrogenation gas at anintermediate point in said catalyst bed.

6. Improvement according to claim 1 in which said hydrogenation gas is amember selected from the group consisting of illuminating gas, coke ovengas, low temperature distillation gas, and similar hydrogen-containinggases in which includes passing said hydrogenation gas in contact withsaid hydrogenation catalyst at a temperature between about -400 C. priorto contact With said hydrogenation gas.

7. Improvement according to claim 1 in which said sulfur-resistantcatalyst is a member selected from the group consisting of oxides,suldes, and mixtures thereof having a base metal selected from the groupconsisting of metals of the 6th and 8th group of the periodic system.

References Cited in the tile of this patent UNITED STATES PATENTS2,037,789 Ipatiel Apr. 21, 1936 2,393,288 Byrns Ian. 22, 1946 2,440,673Iones May 4, 1948 2,620,362 Stiles Dec. 2, 1952 2,694,671 Baumgarten etal Nov. 16, 1954

1. IN THE PROCESS FOR THE CATALYTIC HYDROGENATING REFINING OFHYDROCARBONS IN WHICH A HYDROCARBON RANGING FROM A NORMALLY LIQUID TOSOLID HYDROCARBON IS CONTACTED WITH A HYDROGEN-CONTAINING HYDROGENATIONSGAS IN THE PRESENCE OF A SULFUR-RESISTANT HYDROGENATION CATALYST UNDERCONDITIONS OF ELEVATED TEMPERATURE AND PRESSURE, THE IMPROVEMENT WHICHCOMPRISES EFFECTING SAID CONTACTING IN THE ADDITIONAL PRESENCE OF 5-50%BY VOLUME OF WATER VAPOR BASED ON THE HYDROGENATION GAS.